WO2003103183A1 - Gestion de ressources radio sur la base d'une puissance - Google Patents

Gestion de ressources radio sur la base d'une puissance Download PDF

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Publication number
WO2003103183A1
WO2003103183A1 PCT/IB2002/001999 IB0201999W WO03103183A1 WO 2003103183 A1 WO2003103183 A1 WO 2003103183A1 IB 0201999 W IB0201999 W IB 0201999W WO 03103183 A1 WO03103183 A1 WO 03103183A1
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WO
WIPO (PCT)
Prior art keywords
power
cell
cell interference
interference power
base station
Prior art date
Application number
PCT/IB2002/001999
Other languages
English (en)
Inventor
Christian Braun
Kari Pajukoski
Klas Johansson
Original Assignee
Nokia Corporation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nokia Corporation filed Critical Nokia Corporation
Priority to US10/515,265 priority Critical patent/US7317897B2/en
Priority to AU2002309078A priority patent/AU2002309078A1/en
Priority to PCT/IB2002/001999 priority patent/WO2003103183A1/fr
Publication of WO2003103183A1 publication Critical patent/WO2003103183A1/fr

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
    • H04W52/04—TPC
    • H04W52/30—TPC using constraints in the total amount of available transmission power
    • H04W52/34—TPC management, i.e. sharing limited amount of power among users or channels or data types, e.g. cell loading
    • H04W52/343—TPC management, i.e. sharing limited amount of power among users or channels or data types, e.g. cell loading taking into account loading or congestion level

Definitions

  • the present invention relates to a method and a device for power based radio resource management in wireless radio systems, such as wireless CDMA systems.
  • radio resource management In wireless radio systems, such as the third generation (3G) system, radio resource management (RRM) is responsible for utilisation of the air interface resources. RRM is used in order to guarantee the so-called Quality of Service (QoS), to maintain the planned coverage area and to offer high capacity to the users. RRM can be divided into different functionalities, such as handover control, power control, admission control, load control and packet scheduling functionalities. These functions are required to guarantee the Quality of Service and to optimise the system data throughput with a mix of different bit rates, services and quality requirements.
  • QoS Quality of Service
  • RRM can be divided into different functionalities, such as handover control, power control, admission control, load control and packet scheduling functionalities. These functions are required to guarantee the Quality of Service and to optimise the system data throughput with a mix of different bit rates, services and quality requirements.
  • RRM algorithms can be based on the amount of hardware in the network or on the interference levels in the air interface.
  • the case where the hardware limits the capacity before the air interface gets overloaded is called “hard blocking”.
  • the case where the air interface load is estimated to be above the planned limit is called “soft blocking”. It has been shown that soft blocking based RRM is advantageous as it provides higher capacity than hard blocking based RRM. Therefore, the present invention is concerned with soft blocking based RRM.
  • the air interface load needs to be measured.
  • the estimation of the uplink load of the air interface can be based on the wideband received power level or on throughput.
  • the present invention is engaged with load estimation based on wideband received power.
  • the received power levels can be measured in the base station. Based on such measurements, the uplink load factor ⁇ can be obtained. The corresponding calculations are explained hereinafter with reference to Fig. 1.
  • Fig. 1 shows a base station BS including an antenna 1.
  • the base station BS receives via the antenna 1 an own-cell interference power l 0W n from all intra-cell users connected to the base station BS.
  • the base station receives via the antenna 1 an other-cell interference power l otn from all inter-cell users that are utilizing the same carrier frequency but are connected to other cells than this own cell.
  • the base station BS receives system noise with a system noise power P N via the antenna 1 as well as from its own system components, i.e. system noise is at least partly inherent in a base station BS.
  • the own-cell interference power l own , the other-cell interference power l 0th , and the system noise power P N represent the received wideband interference power, called total received power. This can be expressed by the following equation:
  • the total received power is measured continuously by means of a measurement circuit 3A.
  • the system noise power P N can be measured by the base station by means of a measurement circuit 2.
  • the system noise power PN is commonly estimated at night, when the load is assumed to be small.
  • the own-cell interference power l own and the other-cell interference power l 0 are small as well. This results in
  • the thus estimated noise power PN is then used in an RRM controller 3 to perform RRM functionalities, such as load control and admission control.
  • this method cannot cope with system noise differences between day and night. Furthermore, this prior art method does not allow to determine the other-to-own cell interference ratio / at all, namely the ratio of the other-all interference power l ot h to the own-all interference power / ovvn .Thus, rather conservative noise rise targets have to be used in load control. This degrades system performance.
  • a method for power based radio resource management in wireless radio systems comprising the steps of continuously measuring a total interference power l tot received at a base station, continuously measuring an own-cell interference power l ow ⁇ of all intra- cell users connected to a predetermined cell, received at said base station, continuously estimating a system noise power PN and/or continuously estimating an other-to-own cell interference ratio / based on a number of consecutive measurements of said total interference power l tot obtained by said total interference power l tot measuring step and based on a number of consecutive measurements of said own-cell interference power town obtained by said own-cell interference power l own measuring step, and performing at least one functionality of said radio resource management based on said estimation of said system noise power P N and/or said other-to-own cell interference ratio / ' .
  • a device for power based radio resource management in wireless radio systems comprising: means for continuously measuring a total interference power l tot re- ceived at a base station, means for continuously measuring an own-cell interference power l 0W n of all intra-cell users connected to a predetermined cell, received at said base station, means for continuously estimating a system noise power PN and/or continuously estimating an other-to-own cell interference ratio / based on a number of consecutive measurements of said total interference power l tot obtained by said total interference power l tot measuring means and based on a number of consecutive measurements of said own-cell interference power l ow ⁇ obtained by said own-cell interference power l own measuring means, and means for performing at least one functionality of said radio resource management based on said estimation of said system noise power P N and/or said other-to-own cell interference ration /.
  • the present invention improves the performance of RRM systems, in particular RRM functionalities such as admission control and load control.
  • RRM functionalities such as admission control and load control.
  • the uplink reverse link
  • Knowledge of these parameters is advantageous for certain RRM functionalities such as load control and admission control.
  • These parameters are very useful for radio network planning and optimisation purposes.
  • the present invention enables an online estimation of the other-to-own cell interference ratio / and the system noise power PN- In particular, as the other-to-own cell interference ratio / ' and the system noise power PN are time varying a robust online estimation of these parameters is desirable. Online knowledge of these parameters is useful for e.g. load estimation and identification of cells with interference problems, e.g. a high other-to-own cell interference ratio / ' .
  • the present invention further provides new possibilities to network planning and optimisation, since the interference situation in each cell can be monitored online. Cells with potential problems are easily detected and troubleshooting becomes easier.
  • l to t is said estimated total interference power and PN is said estimated system noise power.
  • the uplink noise rise NR is continuously calculated as
  • the system noise power PN varies over time. For example, man made noise, e.g. from engines etc., is added to the system noise and can be considerably higher at rush hours than at night. Therefore, preferably, the system noise is estimated online, continuously, in order to allow a more accurate load factor /noise rise calculation.
  • the noise rise NR calculation shows that an accurate system noise power P N estimation is advantageous as an error in the system noise power P yields an error in noise rise NR.
  • Fig. 1 shows a base station with a power based radio resource management system according to the prior art
  • Fig. 2 shows a base station with a power based radio resource management system according to an embodiment of the present invention comprising online estimation of system noise power P N and other-to-own cell interference ratio / ' ;
  • Fig. 3 shows a first embodiment of the online estimation of the system noise power P N and the other-to-own cell interference ratio / shown in Fig. 2;
  • Fig. 4 shows a second embodiment of the online estimation of the system noise power PN and the other-to-own cell interference ratio / shown in Fig. 2;
  • Fig. 5 shows a third embodiment of the online estimation of the system noise power P w and the other-to-own cell interference ratio / shown in Fig. 2;
  • Fig. 6 shows a chart illustrating the performance of the system noise power PN estimation
  • Fig. 7 shows a chart illustrating the performance of the other-to-own cell interference ratio / ' .
  • Fig. 1 has been explained with reference to the prior art in order to explain the background of the invention. Therefore, the above explanations with re- gard to Fig. 1 apply to the invention as well, as far as nothing else is described hereinafter.
  • Fig. 2 shows a schematic diagram of a base station BS including an antenna 4 for communication between a radio network, such as a UMTS network utilizing wireless CDMA, and user equipment (not shown), e.g. mobile phones or any other mobile devices.
  • a radio network such as a UMTS network utilizing wireless CDMA
  • user equipment not shown
  • mobile phones e.g. mobile phones or any other mobile devices.
  • Such a base station BS covers a certain area in order to establish a wireless connection between the base station BS and the user equipment(s) being located within this area.
  • Such an area is defined as a cell.
  • l own and l 0th refer only to interference sources within the same frequency band as the base station BS in question. Interference from sources in other frequency bands may arise due to non-perfect filters. For example, UEs operating on another frequency band may have non-negligible adjacent channel leakage into the frequency band of interest, thus causing interference. This interference is covered in the system noise term, PN, and is one of the reasons for the time-varying nature of PN- Furthermore, all the user equipments connected to this certain cell (hereinafter referred as own-cell) cause an own-cell interference.
  • PN system noise term
  • the own-cell interference power that is received at the base station of this own-cell (the power that is caused by all intra-cell users connected to the own-cell) is defined as l o wn- Note that the own cell interference is actually the useful part of the received power, carrying the transmitted user data from the user equipments (UEs).
  • the base station BS receives background noise, in particular via the antenna 4, and a noise caused by the receiver section of the base station BS, namely the receiver noise.
  • This background noise and the receiver noise as well as any other noise that by occur in such a radio system is defined as system noise with a system noise power P -
  • the sum of the other-cell interference power l 0t h, the own-cell interference power l o wn as well as the system noise power PN is hereinafter referred as the total uplink interference power l to t.
  • the total uplink interference power l tot varies over time and is seen by the base station BS at every time instant n as:
  • l t ot (n) l OW n (n) + l oth (n) + P N (n)
  • This total interference power l t0t (n) is continuously measured by a continuous total interference power l tot measurement circuit that is comprised in the base station BS.
  • the base station BS comprises a continuous own-cell interference power lown (n) measurement circuit 6 for continuously measuring the own-cell interference power l OW n (n).
  • Both measurement circuits 5, 6 continuously provide consecutive measured values l to t ⁇ n) and l own (n), e.g. every 100 ms. The provided value should reflect the average value over the measurement period.
  • n can be seen as every measurement reporting instance of the base station BS.
  • the values of l tot (n) and l 0W n (n) are provided to online estimation means 7 that are implemented by software and/or hardware, e.g. by an online estimation circuit.
  • the online estimation means estimates based on the received values hot ⁇ n) and l 0W n ⁇ n) the system noise power PN as well as an other-to- cell interference ratio / that is defined as:
  • the online estimation means 7 assumes that the total interference power l tot and the own-cell interference power l own are continuously measured by the base station BS, in particular by the measurements circuits 5, 6 and utilizes these measurements to estimate the other-to-own cell interference ratio / and the system noise power P N .
  • Fig. 3 illustrates the online estimation circuit 7 of Fig. 2 which is denoted as 307 in Fig. 3. A number of consecutive measurements of the total interference power l tot and the own-cell interference power l own is carried out. Thus a system of equations is set up according to:
  • set up of a system of equations is performed by set up system of equation means 308, e.g. by software implementation or by hardware implementation, e.g. by a corresponding circuit.
  • the online estimation means 7 namely as shown in Fig. 3 as online estimation circuit 307, it is assumed that the other- to-own cell interference ratio / and the system noise power P are fairly constant over the sequence N (independent of n).
  • the equation system can be solved by means of minimum mean square error method (MSE) that is implemented in equation system solving means 309, either by hardware or by software implementation.
  • MSE minimum mean square error method
  • these estimates of the other-to-own cell interference ratio / ' and the system noise power PN are provided to a radio resource management unit 8 that in turn is realized by hardware and/or software implementation.
  • This radio resource management unit 8 performs the functionalities of the radio resource management based on the received estimates of the received system noise power P N and the other-to-own cell interference ratio /.
  • These functionalities are e.g. load control, admission control, packet scheduling, power control, handover control, load estimation and/or identification of cells with interference problems.
  • Fig. 4 shows a further embodiment of the online estimation means 7 shown in Fig. 2 being denoted with 407 in Fig. 4.
  • Online estimation means 407 corresponds mainly to online estimation means 307 and thus comprises set up system of equation means 408 and equation system solving means 409.
  • respective average means 410 for the system noise power estimate PN are provided in order to yield an averaged system noise power value P N
  • average means 411 for the other-to-own cell interfer- ence ratio / estimate are provided in order to yield an averaged other-to-own cell interference ratio value / .
  • Fig. 5 shows a further embodiment of the online estimation means 7 of Fig. 2 being denoted as online estimation means 507 in Fig. 5.
  • Online estimation means 507 is designed in order to provide even better estimates of the signal noise power P N by using averaged values of the received powers hot (n) and l o wn (n) over a predetermined period of time, e.g. 10 s. Further, a corresponding average value of the estimated other-to-own cell interference ratio / is provided as well.
  • online estimation circuit 507 comprises not only set up system of equation means 508 and equation system solving means 509 which correspond to means 308, 408 and 309, 409 respectively, but also comprises average means 510 for the continuously measured total interference power values hot (n) and own-cell interference power l 0W n (n) provided by the measurement circuits 5, 6, respectively.
  • averaged values for the total interference power and the own-cell interference power are provided as l tot and l own .
  • Equation system solving means 509 calculates the other- to-own cell interference ratio namely / as described above.
  • the estimated value for the other-to-own cell interference ratio / is averaged by average means 512 in order to generate an averaged estimated value / for the other-to-own cell interference ratio.
  • the online estimation means 7, 307, 407 and 507 can be implemented by means of hardware and/or software.
  • the above described estimation is not very demanding in terms of computing power and real-time requirements it can be easily implemented in software even though hardware implementation is possible as well.
  • the performance of the estimation is dependent on the number of measurement samples N used in the minimum mean square error estimation. Even though N may be set arbitrarily, a reasonable value is in the range between 5 and 10.
  • Fig. 6 shows the performance of the system noise power estimation P N .
  • P N the performance of the system noise power estimation P N .
  • the system noise power estimation converges to about -100.74 dBm, while the true system noise power was -100.9 dBm (constant), i.e. the noise power was overestimated by 0.16 dB.
  • the uplink average noise rise in this simulation was 2.3 dB.
  • N 10 consecutive measurements were used for every new estimate of the other-to-own cell interference ratio / ' .
  • Fig. 7 shows the other-to-own cell interference ratio / estimation.
  • the present invention is not restricted to the preferred embodiments described above.
  • the above described estimations can be performed in the radio network controller (the equipment in e.g. a radio network subsystem for controlling the use and the integrity of the radio resources) as well.
  • the estimation have not necessarily to be performed in the base station.
  • the base station as well as the radio network controller comprise a radio resource management functional part which is suitable to implement the above described estimations.
  • the preferred embodiments may vary within the scope of the attached claims.

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

L'invention concerne un procédé et un dispositif de gestion de ressources radio sur la base d'une puissance dans des systèmes radio sans fil tout en mesurant de façon continue une puissance perturbatrice totale et <i>Itot</i> et une puissance perturbatrice de cellule propre <i>Iown</i> ainsi qu'une estimation continue de la puissance de bruit du système <I>P<SB>N</SB></I> et/ou du coefficient de perturbation de cellule <i>i</i> à s'approprier basé sur ces mesures. Ainsi des valeurs améliorées <I>P<SB>N</SB></I> et/ou <i>i</i> sont produites, ce qui permet un calcul plus précis de l'augmentation du bruit/facteur de charge.
PCT/IB2002/001999 2002-06-04 2002-06-04 Gestion de ressources radio sur la base d'une puissance WO2003103183A1 (fr)

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Application Number Priority Date Filing Date Title
US10/515,265 US7317897B2 (en) 2002-06-04 2002-06-04 Power based radio resource management
AU2002309078A AU2002309078A1 (en) 2002-06-04 2002-06-04 Power based radio resource management
PCT/IB2002/001999 WO2003103183A1 (fr) 2002-06-04 2002-06-04 Gestion de ressources radio sur la base d'une puissance

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WO2007026054A1 (fr) * 2005-09-02 2007-03-08 Nokia Siemens Networks Oy Procede et agencement pour la gestion de ressources radio
CN100411475C (zh) * 2004-08-12 2008-08-13 华为技术有限公司 移动通信系统中上行负载估计方法

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US7949342B2 (en) * 2004-01-08 2011-05-24 Interdigital Technology Corporation Radio resource management in wireless local area networks
FR2900529A1 (fr) * 2006-04-26 2007-11-02 France Telecom Gestion de ressources radio dans un reseau de telecommunications radio
KR101567368B1 (ko) * 2009-07-02 2015-11-09 삼성전자주식회사 광대역 무선통신 시스템에서 셀 간 간섭 감소를 위한 자원 관리 장치 및 방법
US9549408B2 (en) 2012-06-04 2017-01-17 Telefonaktiebolaget Lm Ericsson (Publ) Interference congestion control
US9020548B2 (en) * 2012-06-04 2015-04-28 Telefonaktiebolaget L M Ericsson (Publ) Other cell interference estimation
CA2997905A1 (fr) * 2015-09-08 2017-03-16 Telefonaktiebolaget Lm Ericsson (Publ) Localisation de frequence d'une cellule primaire (pcell)

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WO2000055976A2 (fr) * 1999-03-15 2000-09-21 Telefonaktiebolaget Lm Ericsson (Publ) Regulation de puissance adaptative dans un systeme de radiocommunication

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN100411475C (zh) * 2004-08-12 2008-08-13 华为技术有限公司 移动通信系统中上行负载估计方法
WO2007026054A1 (fr) * 2005-09-02 2007-03-08 Nokia Siemens Networks Oy Procede et agencement pour la gestion de ressources radio

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US7317897B2 (en) 2008-01-08
US20050153660A1 (en) 2005-07-14
AU2002309078A1 (en) 2003-12-19

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